Generators are used in a wide variety of applications to provide AC or DC power to power electrical tools or implements. In particular, portable generators typically make use of an internal combustion engine which drives a rotor having a plurality of permanent magnets affixed thereto, and where the rotor is coupled to an output shaft of the engine. The rotor is disposed within a stator. Cooperatively these components form a portion of a permanent magnet generator.
Typically one or more electronic circuit boards are disposed adjacent the rotor and stator. Since these components can become quite hot during prolonged use, it is necessary to provide a cooling airflow that not only cools both the rotor and stator, but also the electronic circuit boards that control operation of the generator. Traditionally, this has been accomplished by the use of more than one fan. For example, one fan may be positioned to draw air in through an opening in a housing within which the stator and rotor is disposed, while a separate fan is positioned within a different location in order to draw a cooling airflow around the electronic circuit boards.
Other attempts at addressing the important issue of cooling the internal components of a generator have involved the use of a single fan which generates a main airflow, which is then subsequently divided and channeled into different areas of the generator.
In view of the foregoing, there still exists a need for even more effective cooling of the internal components of a generator. More particularly, there still exists a need for a cooling arrangement which can effectively cool the stator/rotor assembly located within a housing of the generator, as well as the electronic circuit board(s) located remotely from the stator/rotor assembly. It would be particularly desirable to provide an arrangement wherein a single fan disposed strategically within the generator could be used to generate two distinct cooling airflow paths to optimally cool both the rotor/stator assembly as well as an electronics circuit board that is located remotely from the rotor/stator assembly. The use of a single cooling fan that more effectively cools the stator/rotor assembly, as well as the electronic circuit board(s) of the generator would serve to reduce the overall cost of the generator, further improve reliability and simplify the construction of the generator.